The present invention, in some embodiments thereof, relates to industrial control systems and, more specifically, but not exclusively, to monitoring of industrial control systems for security, maintenance, and redundancy.
Supervisory control and data acquisition (SCADA) systems, or any type of industrial control systems (ICSs), are where computer controlled systems interact with real-world processes by monitoring and controlling the analog and digital input and output from devices, such as pumps, valves, heaters, and the like. ICSs are at the center of today's technological infrastructures. ICSs are used to control and monitor from the most crucial processes, such as infrastructures for power generation, electrical transmission grids, water distribution, and transportation control, down to low scale ventilation, heating, and gas control in public or private facilities.
ICSs are comprised of programmable logic controllers (PLCs), SCADA data networks, operator and supervisor terminals, management terminals, and the like. The PLCs devices are connected to physical devices, such as pumps, meters, valves, heaters and the like, and control these physical devices using hardware interfaces, such as analog and/or digital input and/or output (I/O) electrical conductor lines, referred to herein as I/O lines. The PLCs frequently use a system bus design to attach I/O modules to the PLC processing unit, and the I/O modules contain electronics to control the output conductors and perform measurements on the input conductors. By manipulating the I/O lines in a certain order, the operation of the facility is implemented. The physical devices are operated by the PLC according to embedded logic, and each PLC is designed to work autonomously, often in groups where each PLC might control part of the process. Select information and statuses gathered by the PLCs are transferred to operator and/or supervisor terminals who have limited control of the operations according to predefined constraints, such as manual overrides of certain devices and/or operations when needed. Higher level information is transferred to management terminals for executive monitoring of the operations.
ICSs may be described as centralized and highly distributed control systems where most of the logic is performed on the level of the PLCs, which have exclusive real world connection to the physical devices. The PLC's operational logic runs automatically in real time till the logic is changed, parameters are changed, or a manual override is sent from a control terminal. ICSs are designed to provide high reliability and environmental protection, and major efforts were done to reach high values of mean time between failures (MTBF). Hence the control systems were designed to be robust, autonomous, and easily overridden by the operator and/or programmer when needed.
Current security techniques for ICS include network level security using firewalls, internet packet diodes and high security level password protected gateways. These security techniques are designed to prevent unauthorized access through the internet.